The long range objective of the research program is to elucidate the mechanism by which a DNA tumor virus can alter normal regulation of cellular growth to produce a state of uncontrolled growth as is characteristic of transformed cells. To better understand the nature of DNA tumor virus gene products and their effects on host cell regulation, I plan to identify, map and study the function of specific viral genes. Specifically, I propose to continue the construction and analysis of SV40 deletion mutations which I have under way and to extend the techniques developed in the SV40 system to the analysis of the Adenovirus type 5 genome.